The other day i was having an issue with a button which had a movie clip layered on top of it. I assumed that the movieclip on top of the button would disable the button mouse events but after running my application, the button was still firing an onRelease event (even though you could not see it on stage). After a bit of research, i discovered that setting the ‘visible’ property to false on a button/movieclip completely disables the mouse events for the button/movieclip, as well as hiding it from the stage. I’m finding this very useful for situations where i would like to dynamically enable or disable the mouse events of a button/movieclip.